/*****************************************************************************
 * bs.h :
 *****************************************************************************
 * Copyright (C) 2003-2008 x264 project
 *
 * Authors: Loren Merritt <lorenm@u.washington.edu>
 *          Jason Garrett-Glaser <darkshikari@gmail.com>
 *          Laurent Aimar <fenrir@via.ecp.fr>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02111, USA.
 *****************************************************************************/

/*****************************************************************************
 * bs.h :
 *****************************************************************************
 * Copyright (C) 2009~2010 xavs project
 * Authors: Jianwen Chen <jianwen.chen.video@gmail.com>
 * This code is modified on x264 project and will follow the license of x264
 *****************************************************************************/


#ifdef _XAVS_BS_H_
#warning FIXME Multiple inclusion of bs.h
#else
#define _XAVS_BS_H_

typedef struct bs_s
{
  uint8_t *p_start;
  uint8_t *p;
  uint8_t *p_end;

  int i_left;                   /* i_count number of available bits */
  int i_bits_encoded;           /* RD only */
} bs_t;

static inline void
bs_init (bs_t * s, void *p_data, int i_data)
{
  s->p_start = p_data;
  s->p = p_data;
  s->p_end = s->p + i_data;
  s->i_left = 8;
}
static inline int
bs_pos (bs_t * s)
{
  return ((int) (8 * (s->p - s->p_start) + 8 - s->i_left));
}
static inline int
bs_eof (bs_t * s)
{
  return (s->p >= s->p_end ? 1 : 0);
}
static inline uint32_t
bs_read (bs_t * s, int i_count)
{
  static uint32_t i_mask[33] = { 0x00,
    0x01, 0x03, 0x07, 0x0f,
    0x1f, 0x3f, 0x7f, 0xff,
    0x1ff, 0x3ff, 0x7ff, 0xfff,
    0x1fff, 0x3fff, 0x7fff, 0xffff,
    0x1ffff, 0x3ffff, 0x7ffff, 0xfffff,
    0x1fffff, 0x3fffff, 0x7fffff, 0xffffff,
    0x1ffffff, 0x3ffffff, 0x7ffffff, 0xfffffff,
    0x1fffffff, 0x3fffffff, 0x7fffffff, 0xffffffff
  };
  int i_shr;
  uint32_t i_result = 0;

  while (i_count > 0)
  {
    if (s->p >= s->p_end)
    {
      break;
    }

    if ((i_shr = s->i_left - i_count) >= 0)
    {
      /* more in the buffer than requested */
      i_result |= (*s->p >> i_shr) & i_mask[i_count];
      s->i_left -= i_count;
      if (s->i_left == 0)
      {
        s->p++;
        s->i_left = 8;
      }
      return (i_result);
    }
    else
    {
      /* less in the buffer than requested */
      i_result |= (*s->p & i_mask[s->i_left]) << -i_shr;
      i_count -= s->i_left;
      s->p++;
      s->i_left = 8;
    }
  }

  return (i_result);
}

static inline uint32_t
bs_read1 (bs_t * s)
{

  if (s->p < s->p_end)
  {
    unsigned int i_result;

    s->i_left--;
    i_result = (*s->p >> s->i_left) & 0x01;
    if (s->i_left == 0)
    {
      s->p++;
      s->i_left = 8;
    }
    return i_result;
  }

  return 0;
}
static inline uint32_t
bs_show (bs_t * s, int i_count)
{
  if (s->p < s->p_end && i_count > 0)
  {
    uint32_t i_cache = ((s->p[0] << 24) + (s->p[1] << 16) + (s->p[2] << 8) + s->p[3]) << (8 - s->i_left);
    return (i_cache >> (32 - i_count));
  }
  return 0;
}

/* TODO optimize */
static inline void
bs_skip (bs_t * s, int i_count)
{
  s->i_left -= i_count;

  while (s->i_left <= 0)
  {
    s->p++;
    s->i_left += 8;
  }
}


static inline int
bs_read_ue (bs_t * s)
{
  int i = 0;

  while (bs_read1 (s) == 0 && s->p < s->p_end && i < 32)
  {
    i++;
  }
  return ((1 << i) - 1 + bs_read (s, i));
}
static inline int
bs_read_se (bs_t * s)
{
  int val = bs_read_ue (s);

  return val & 0x01 ? (val + 1) / 2 : -(val / 2);
}

static inline int
bs_read_te (bs_t * s, int x)
{
  if (x == 1)
  {
    return 1 - bs_read1 (s);
  }
  else if (x > 1)
  {
    return bs_read_ue (s);
  }
  return 0;
}

static inline void
bs_write (bs_t * s, int i_count, uint32_t i_bits)
{
  if (s->p >= s->p_end - 4)
    return;
  while (i_count > 0)
  {
    if (i_count < 32)
      i_bits &= (1 << i_count) - 1;
    if (i_count < s->i_left)
    {
      *s->p = (*s->p << i_count) | i_bits;
      s->i_left -= i_count;
      break;
    }
    else
    {
      *s->p = (*s->p << s->i_left) | (i_bits >> (i_count - s->i_left));
      i_count -= s->i_left;
      s->p++;
      s->i_left = 8;
    }
  }
}

static inline void
bs_write1 (bs_t * s, uint32_t i_bit)
{
  if (s->p < s->p_end)
  {
    *s->p <<= 1;
    *s->p |= i_bit;
    s->i_left--;
    if (s->i_left == 0)
    {
      s->p++;
      s->i_left = 8;
    }
  }
}

static inline void
bs_align_0 (bs_t * s)
{
  if (s->i_left != 8)
  {
    *s->p <<= s->i_left;
    s->i_left = 8;
    s->p++;
  }
}
static inline void
bs_align_1 (bs_t * s)
{
  if (s->i_left != 8)
  {
    *s->p <<= s->i_left;
    *s->p |= (1 << s->i_left) - 1;
    s->i_left = 8;
    s->p++;
  }
}
static inline void
bs_align (bs_t * s)
{
  bs_align_0 (s);
}



/* golomb functions */

static inline void
bs_write_ue (bs_t * s, unsigned int val)
{
  int i_size = 0;
  static const int i_size0_255[256] = {
    1, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
    6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8
  };

  if (val == 0)
  {
    bs_write1 (s, 1);
  }
  else
  {
    unsigned int tmp = ++val;

    if (tmp >= 0x00010000)
    {
      i_size += 16;
      tmp >>= 16;
    }
    if (tmp >= 0x100)
    {
      i_size += 8;
      tmp >>= 8;
    }
    i_size += i_size0_255[tmp];

    bs_write (s, 2 * i_size - 1, val);
  }
}

static inline void
bs_write_se (bs_t * s, int val)
{
  bs_write_ue (s, val <= 0 ? -val * 2 : val * 2 - 1);
}

static inline void
bs_write_te (bs_t * s, int x, int val)
{
  if (x == 1)
  {
    bs_write1 (s, 1 & ~val);
  }
  else if (x > 1)
  {
    bs_write_ue (s, val);
  }
}

static inline void
bs_rbsp_trailing (bs_t * s)
{
  bs_write1 (s, 1);
  if (s->i_left != 8)
  {
    bs_write (s, s->i_left, 0x00);
  }
}

static inline int
bs_size_ue (unsigned int val)
{
  static const int i_size0_254[255] = {
    1, 3, 3, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 7, 7,
    9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
    11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
    11, 11, 11, 11, 11, 11, 11, 11, 11, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
    13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
    13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13,
    13, 13, 13, 13, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
    15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15
  };

  if (val < 255)
  {
    return i_size0_254[val];
  }
  else
  {
    int i_size = 0;

    val++;

    if (val >= 0x10000)
    {
      i_size += 32;
      val = (val >> 16) - 1;
    }
    if (val >= 0x100)
    {
      i_size += 16;
      val = (val >> 8) - 1;
    }
    return i_size0_254[val] + i_size;
  }
}

static inline int
bs_size_se (int val)
{
  return bs_size_ue (val <= 0 ? -val * 2 : val * 2 - 1);
}

static inline int
bs_size_te (int x, int val)
{
  if (x == 1)
  {
    return 1;
  }
  else if (x > 1)
  {
    return bs_size_ue (val);
  }
  return 0;
}



#endif
